Circuit interrupter



Feb. 7, 1933. H. J. LINGAL 1,896,779

CIRCUIT INTERRUPTER Filed Feb. 16, 1932` 2 Sheets-Shea? l 1 9 i l `\L 2.5 v WITNESSESI INVENTOR BY 2 ATToRN Y MPatented Feb. 7, y'

UNi'rED. sTATEsf-'PATEN'T OFFICE HARRY J. LINeA'L, .or wILmNsia'Ua'G, rENNsYLvANIA-AssIGNORiTO wEsrINGHoUsE nnnernrc a IANUFACTURING COMPANY, A CORPORATION or rnNNsYLvAmA IT INTERRUPTER Application mea February 1e, 1932. serial No'. seams.

extinguishing large current arcs in air orv gas.

The arc extinguisher of my invention isV of the cold-cathode, spaced-plate type. The arc is established adjacent to the extinguisher proper, and is moved, by magnetic action,

through a converging slot into the extinguishing chamber which includes a plurality of spaced conducting plates. :These vspaced conducting plates sub-divide the arc` into a pluralit of short arcs which, under the influence o the flux of a radial field, rotate at a very high velocity-while existing v in the cold cathode state-until they become extinguished.

My invention is a further improvement of circuit breakers of the type disclosed in Patent No."1,784,760, issued to Joseph Slepian, December 9, 1930, and certain subject matter described here-in is claimed in the applications for Letters Patent, Serial No. 510,981, filed January 24, 1931, by Frederick B. Johnson, and Serial No. 511,010, filed January 24, 1931, by Robert C. Dickinson, all of which are assigned to the assignee of the present invention.'

An object of my invention is to rovide an arc extinguishing structure that s all be effective and reliable in operation and that shall be economical to manufacture.

Another object of my invention is to generally simplify the construction of the abovementioned type of arc. extinguisher by providing spacing and positioning means integral with the plates themselves.

A further object of myinvention is to provide means integral with the unit plates of the arc extinguishing structure for ventilating each of the short arcs.

A further object of my invention is to provide Ventilating passages of a suilicientcross sectional area to prevent the building up of gas pressure in advance of the arc as it moves into the spaces between the conducting members, and thus permit the use of a relatively weak blow-in field, without the provision of heavy multi-turn blow-in coils,- for moving the arc in said spaces.

A further object of: my invention is to Aprovide means for defining a path wherein each ,of the short arcs isl caused to move, which means shall prevent those arcs from movingout of the structure.

A still further object of my invention is to provide a composite plate for use in are extinguishing structures that shall have a central portion, upon which the short arcs are caused to rotate, of non-magnetic conducting material, and an Outer portion of magnetic material; the outer portions of said com osite plates'having raised means thereon or engaging and positioning vthe central portion of 'said composite plates, for

spacing said composite plates, and for establishing passages therebetween.

The features of my invention which I believe to be new are partly pointed out. in the appended claims. For a full understanding oftheprinciples of the invention and the best mode ofkapplying same, reference may be had Vto the accompanying drawing, in which 'Figure 1 is a view in elevation of the arc extinguishing structure of my invention taken on the line I-I of Fig. 2.

Fig. 2 is a sectional view of my arc extinguishing structure taken along the line IIII of Fig. 1, and illustrating the contact members of a circuit interrupter associated' therewith.

Fig. 3 is a sectional view taken along the line III- III of Fig. 2.

Fig. 4 is a fragmentary view of the stack vof plates taken on the line IV--IV of Fig.

Fig. 5 is an exploded perspective view of my arc extinguishing structure. In view of the limited available space, only a few of the centrally disposed plates have kbeen shown.

Inasmuch as my invention does not pertain tol circuit breaker operating mechanisms, and since those mechanisms are well known in the art, I have illustra-ted only the Contact member part of a circuit breaker in association with my arc extinguishing structure. A diagrammatical representation has been provided in order to show the electrical connections involved. I prefer to mount the structure of my invention adjacent to the As shown in Fig. 2, the base plate 1, which is constructed of copper and which forms the base of the arc extinguishing structure 10, terminates ina raised portion 2 which is used as the mainstationary Contact. The contact members 6 and 7 are', respectively, the main moving contact and the auxiliary moving contact. These contact members are connected to the line 3 and to the top plate 40 of the arc extinguishing structure as shown by the diagrammatical representation. Another i plate member 30, likewise of copper, is provided: this is connected to the plate member 1 through a coil assembly 4, and has intelUral therewith a raised portion 33 and an arc resisting portion 34 which together form the auxiliary stationary contact 35. The portion 34 of arc resisting material is disposed on top of the projection 33 and is used to provide a facing for the contact 35.

The arc resisting material which I prefer to use is a silver-tungsten alloy composed of 40% silver and 60% tungsten. Any conduct- 1ng material, however. having similar prop- -erties wouldbe equally satisfactory.

During the opening and closing of the circuitbreaker, the electrical contact is first established and finally interrupted between the auxiliary moving contact 7 and the auxiliary stationary contact 35. The main moving contact 6 engages the main stationary contact 2 only when the breaker is in the fully closed position. This construction is in accordance with the usualhigh voltagehigh current circuit breaker design in which separate members are used for carrying the normal line current and for establishing the arc when the circuit is interrupted. This construction is especially desirable in that low resistance contact may be preserved between the main contact members despite any pitting or roughening resulting from the heat of the arc.

Referring more particularly to the drawings, myinvention comprises, generally, a stack of tially at right angles to the 'arc path, and having means associated therewith for moving the arc into the spaces between these composite plates and there rotating it at high speed until extinguished. The base plate 1 has rigidly aliixed thereto atubular iron member 17 which is threaded at the free end 37. An insulating tube 8 and two insulating washers 9 are associated with the tubular member 17 and serve to insulate that member from the remainder of the structure.

Assembled about the insulating member 8 screw 24.

' 30 is an iron plate 50 which composite plates disposed substanelement in the stack structure 10 is the coil assemblage 4 which is provided for setting up the radial field within 'the arc extinguisher. This assemblage comprises a pole piece 11 of magnetic material, preferably of iron, having a depression 12 therein. The depression 12 has an openin 15 the function of which will be explaine later. The pole piece 11 is of substantially the same dimensions as the other plates of the structure and it has an opening 14 to permit the passage of the tubular iron member 17. The coil 20 is composed of several turns of copper ribbon and has conducting terminals 21 and 23. This coil is assembled adjacent to the pole piece 11 and is insulated therefrom by the insulating member 16. The terminal 21 of the coil 20 passes through the opening 15 in the pole piece 11 and is electrically connected with the base plate 1 by means of the screw 24 and the nut 26-the hole 22 in the terminal 21 being adapted to receive the shank of An insulating plate 27 having a cut out portion 28 is assembled adjacent to the coil 20, on the side opposite the pole piece 11, and serves the function'of insulating the pole piece 1l and the coil 20 from the remainder of the structure. The terminal 23 of the coil 20 extends through the cut out portion 28 and is welded to the conducting plate 30. Surrounding the conducting plate is the top plate of the coil assemblage 4. The plate 50 has cut out portions 52 and 53, and the portions 51 and 54 which extend outwardly from the plane of the plate. The cut out portions 52 and 53 define a converging slot and an lannular opening, respectively, of substantially the same outline as the conducting plate 30; the raised portions 54 form a recess into whlch the conducting plate 30 fits.

The next unit in the arc extinguishing structure is an insulating plate 56 having cut out portions 57 converging slot and an annular opening of somewhat smaller dimensions than the corresponding openings 52 and 53 in the plate 50. The next elements in the structure are five composite plates 18, each separated from the other and from the adjoining parts of the structure, by an insulating plate 56. (Only one of' the composite plates is shown in Fig. 5.) The top plate 40 is of heavy gauge copper plate and has a portion 41 which projects outwardly from the plane of the plate. This projection 41 delines a recess for receiving the auxiliary moving contact 7 when the breaker is in the open position.

The coil assemblage 4, the composite plates 18, the top plate. 40, and the insulating washers 9, all have a common opening 31 for receiving the insulating tube 8.'

and 58 which define a A assembled arc extinguishing structure these slots align to form a converging wedge shaped opening 69 leading from the arc path into the structure proper.

Each of the composite plates 18 comprises an iron plate and a copper plate 60 or 70. Ineach of the iron plates 50, as has been previously pointed out, there is a cut out portion in the center defining a converging slot 52 and an annular cut out portion 53 connected therewith. The edges 54 of both of the cut out portions have been pressed outwardly from the plane of the plate in such manner as tovform a recess of substantially the same outline as the copper plates 60 and 7 0. In addition to the pressed out edges 54, there are four portions 51 extending outwardly from the plane of the plate; these portions 51 are utilized for spacing the composite plates and in conjunction with the opening 55 form a Ventilating passage 75 through the arc extinguishing structure. The completed composite plate 18 thus comprises an edge portion 50 of magnetic ma-- terial having a suitable recess-defined by the raised portions 54--for the positioning of the central portion or 70, and a central portion 60 or 70 of non-magnetic conducting material. In this embodiment of my invention, copper is used for the central portions 60 and 7 0. The outer portion 50 of all of the composite pla-tes is the same, but the Iinner portion comprises either a plate 60 or a plate 70.

Each of the copper plates 60 has a portion 61 substantially circular in outline and two projecting sections 63 and 64 between which is the slot 65. The central portion 61, has the common opening 31 for receiving the insulating tube 8 and, in addition, has a cut out portion 62 which prevents the building up of eddy currents within the copper plate during the operation of the extinguisher.

The copper plates are exactly the same asl the copper plates 60 except for the position of the cut out portion 62 which, in the plates 70, is located approxmately 180o from the position occupied by the slot 62 in the plates 60.

In the assembled arc extinguishing structure, each of the composite plates 18 havinga central portion 60 is disposed adjacent to a composite plate 18 having a central por,- tion 70. This is done in order that the cut out portions 62 shall not align to form a con- 'structure may best be described by considering the sequence of events following the opening of the circuit breaker contacts. Assuming that the contacts begin to separate when the line potential is such that the current flows down through the plate member 1, thence through the main contacts 2 und 6,

and out Ofiline 3, the first step is the separation of the main fixed contacts 2 and the main moving contact 6. The arc is not established at this time, but the path of current through the interrupter is somewhat changed. Prior to the opening of the main contacts, practically all of the current flow was in through the base plate 1 and out through the main contacts. A small amount of current did flow from base plate 1 through the conducting termnal 21 of the coil structure 4, thence through the coil 20, the plate 30, and out through the auxiliary contacts 34 and 7. When the main contacts open, however, all of the current flow is now from the base plate l, the conducting terminal of the coil assemblage 4, the coil 20 and its associated plate 30, and the arcing contacts 34 and 7. Next, the contacts 7 and 35 separate and the arc is established therebetween. The separation of the auxiliary moving contact 7 and the arc'ng contact 35 increases until the moving contact 7 has moved to the full open position, or that is until the moving contact 7 has moved into the recesses 41 ofthe top plate 40. It is to be noted, at this point, that the top plate 4() of the arc extinguishing structure is at all time electrically connected with the moving contacts 6 and 7, and the line 4. Thus, when the arc is completely established, it exists between the arcing contact 35 and the top plate 40. Simultaneously, with the formation ot the are, the magnetic circuit created by the adjacent slotted plates 50 of magnetic material causes the arc to begin to move through the converging slot 69, formed by the openings 65 and 58, toward the copper conducting plates 60 and 70. As the arc moves through the converging slots 65 of the copper conducting plates 60 and 70, the cross section ofthe arc is decreased. This decrease in the cross section facilitates the breaking up of the single long are, which exists during the initial stages of the arc extinguishing process, into short arcs which exist as coldl cathode arcs in the spaces between the composite plates 18.

The movement of the arc is comparatively rapid, and the short arcs are established al- 60 and 70. The path of travel of each of the short arcs is defined by the cut out portion 57 in the insulating plates 20. These insulating plates 50 also serve to keep the short arcs from moving out of the stack structure by providing insulation across the vent openings 55 and 75.

The rapid motion of the short arcs and the accompanying rapid removal of the heatmade possible by the vent openings 55 and 75, and by the intimate conductive'relationship of the copper and the magnetic platesall combine to effect a very rapid extinguishmeilt of each of the individual arcs.

The composite plates 18 are assembled in such relation to the coil 20 that the converging slots 65 are disposed in substantially the same direction that the short arcs are caused to rotate by the radial field. This is done in order to further facilitate the establishment of the short arcs and to reduce the burning of the edges of the slotsl 65.

It will thus be seen that I have disclosed an arc extinguishing structure that is reliable and effective in operation, that is simple and economical to manufacture, and that has means integral with the composite plates of the structure for venting each of the small arcs While, at the same time, retaining those small arcs within the structure.

While, in accordance with the patent statutes I have given the foregoing details of a practical embodiment of my invention. it is to be understood that many of these y are merely illustrative and variations of their precise form will be both possible and in some applications desirable. I desire. therefore, that the language of the accompanying claims shall be granted the broadest reasonable construction, that my inventionbe limited only by what is explicitly stated in the claims and by the prior art. a

I claim as my invention:

1. In an arc extinguishing structure, a plurality of plates of conducting material, and a plurality of plates of magnetic material; some of said plates of magnetic material having raised edge portions.

2. In an arc extinguishing structure, a plurality of composite plates, some of said coinposite plates having a portion of non-magnetic material, a portion of magnetic material, and portions extending outwardly from the plane of one vof said plates; said outwardly extending portions providing spaces between said plates.

3. In an are extinguishing structure, a plurality of plates of conducting -matera1, means for moving the arc including a plurality of plates of magnetic material, and means for spacing said plates' including portions raised from the surface of some of said plates.

4. In an arc extinguishing structure, a plurality of plates of conducting material, and a. plurality of plates of magnetic material; some of said plates of magnetic material having depressions therein around portions of the edges thereof for engaging said conducting plates.

5. Inan arc extinguishing structure, a plurality of composite plates, each of said composite plates having a portion of non-magnetic conducting material and a portion of magnetic material; some of said composite plates having portions extending outwardly from the plane of said plates; said outwardly extending portions providing Ventilating passages between said plates.

6. In an arc extinguishing structure, a plurality of composite plates, and insulating means for spacing said plates, each of said composite plates having a. portion of nonmagnetic conducting material and a portion lof magnetic material; some of said composite plates having. in addition, portions extending outwardly from the plane of said plates for providing Ventilating passages through said structure.

7. In an arc extinguishing structure. a plurality of plates of non-magnetic conducting material, and a plurality of plates of magnetic materiaLeach of said plates of magnetic material having portions extending outwardly from the plane thereof for defining a recess of substantially the same outline as said plates of non-magnetic conducting material; said plates of non-magnetic conducting material engaging saidreeess and being there retained.

8. In an are extinguishing structure. apluralityv of sheets of conducting material having slots therein. and means'for moving the are in said slots comprising a plurality of sheets of magnet-ic material having depressions therein and having narrowed portions for providing a. magnetic lield of'inereased strength adjacent to said slots: said depressions in each of said sheets of magnetic material having substantiallv the same outline as said sheets of conducting material; each of said sheets of conducting material engaging said depressions in one of said sheets of magneti(l material and being there retained.`

pressed portions therein; said members of magnetic material being disposed in planes substantially parallel with said sheets of nonmagnetic conducting material; said depressed portions of said'members of magnetic material providing means for separating said members of magnetic material and forming Ventilating passages therebetween.

10. In an arc extinguishing structure, a plurality of composite plates, each of said composite plates having a portion of nonmagnetic material and a portion of magnetic material having a raised part, and means for giving the arc a rotary motion on said portion of non-magnetic material; each of said portions of non-magnetic material engaging said raised part of said portion of magnetic material and being therein retained.

which overlap the corresponding-e 11. In an arc extinguishing structure, a plurality of composite plates, each of said plates having a portion of non-magnetic conducting material and a portion of magnetic material, means for giving the are a rotary motion on said portions of non-magnetic conducting material, and insulating sheets defining a passage in which the arc may be moved between said plates; each of said portions of magnetic material having raised parts thereon for engaging the associated portion of conducting material.

12. In an arc extinguishing structure, means for extinguishing the arc comprising a plui ality of composite plates and insulating members defining an annular path for the arc;`each of said composite plates having a central portion of non-magnetic conducting material and edge portions of magnetic material, said central portion of said composite plates engaging depressions in said edgeportions and being therein retained; said insulating members extending across the joints between said central and said edge portions adjacent the said arc path.

13. In an arc extinguishing structure, a plurality of spaced plates of conducting material, each of said lates having a slot therein and some of sai plates having means including portions extending outwardly from the plane of said plates for providing Ventilating passages.

14. In an arc extinguishing struct ire, a plurality of conducting plates of non-magnetic material, each of said conducting plates having associated therewith a plate of magnetic material and an insulating member; some of said plates having portions extending outwardly from the plane thereof for spacing said plates.

15.4In an arc extinguishing structure, a plurality of non-magnetic conducting members, each of said non-magnetic conducting members having a plate of magnetic lmaterial associated therewith, each of said plates of magneticv material having edge (portions ge portions of the associated non-magnetic conducting member.

16. In an arc extinguishing structure, a

plurality of plates of non-magnetic conduct-A ing material, anda plurality ofplates of magnetic material having annular cut out p0rtions therein, some of said plates having portions extending outwardly from the plane thereof; the edges of each of said cut out portions being in overlapping engagement with one of said non-magnetic conducting plates.

17. In an arc extinguishing structure, a plurality of plates of non-magnetic conducting material, a plurality of plates of insulating material, and a plurality of plates 0f magnetic material, said insulating plates and said plates of magnetic material having annular cut out portions therein; said plates of magnetic material having raised portions extending outwardly from the plane thereof; said raised. portions providing Ventilating passages through said arc extinguishing structure.

18. In an arc extinguishing structure, a plurality of plates of non-magnetic conducting material, a plurality of insulating members, and a plurality of plates of ma netic material; said insulating members an said netic material having raised portions extending outwardly from the plane of said plates; said raised portions spacing said plates and providing Ventilating passages therebetween; said insulating plates extending completely across the Ventilating passages provided by said raised portions.

19. In an arc extinguishing structure, a plurality of composite plates disposed Substantially perpendicular to the arc for subdividing said arc into a plurality of short arcs, and a plurality of insulating plates; each of said composite plates having a" central portion of non-'magnetic conducting inaterial and an edge portion of magnetic material; some of said composite plates having raised portions for providing Ventilating passages between successive composite plates; said insulating plates having portions removed to provide a passage for permittin the arc to move into contact relationship wit the central portion of said composite plates, and having portions extending across said Ventilating spaces. f

20. In an arc extinguishing structure, a plurality of plates of non-magnetic conducting material, a plurality of insulating plates, and a plurality of plates of magnetic material; said insulating plates and said plates of magnetic material having annular cut out portions therein; said cut out portions having substantially the same outline as saidI -plates of magnetic material having annular cut out portions therein, said plates of magsions therein; said depressions engagin the edge portions of said non-magnetic p ates and providing Ventilating spaces through said structure. 21. In an arc extinguishing structure, a plurality of plates of conducting material disposed substantially perpendicular to the arc path, and s acing means for said plates, some of said p ates of conducting material 10 having portions extending outwardly from the plane of said plates for providing ventilating passages through said structure.

22. In an arc extinguishing structure, a plurality of plates of conducting material disposed substantially perpendicular to the arc path, means for moving the arc into contact with said plates so as to cause the arc to sub-divide into a plurality of short arcs, means for giving the short arcs a rotary motion on said plates, and means of insulating material for defining a passage wherein the arc may be moved between said plates, said l plates having raised portions for separating the-adjacent plates in said structure a distance greater than the thickness of said means of insulating material and thereby providing Ventilating passages through said arc extinishing structure. l y Y 23. In an arc extinguishing structure, a

plurality of plates of conducting material,

4and a lurality of plates of insulating material or spacing said plates of conducting material, each of said spacing plates havin a centrally disposed cut-out portion througlgi which the arc may play between said plates of conducting material, said plates of conducting material having raised portions extending outwardly from the plane thereof for providing Ventilating passages through 40 said arc extinguishing structure.

24. In an arc extinguishing structure, a pluralityof plates of conducting material, and a plurality of plates of insulating material for 'spacing said plates of conducting material, each of said spacing plates having a centrally disposed cut-out portion through which the arc may play between said lates of conducting material, said lates o conducting material having raise ortions ex'- tending outwardly from the p ane thereof for providing Ventilating passages through said arc extinguishing structure, said lates of insulating material extending comp etely across the Ventilating passages provided by said raised portions.

In testimony whereof, I have hereunto subscribed my name this 13th day of February,

HARRY J. LINGAL. 

